MONOTONE Report Summary

Flexible software framework for modularising a multi-ink printing process with strategies for prediction, diagnosis, set points and batch-adaptivity.

The developed system provides a flexible software framework for modularising a halftone printing process, possibly consisting of more than one printing stages, as is the case, e.g., in industrial tile printing. It has the following characteristics:

- Setup and training is done in an initialisation step prior to production- The prediction algorithm is based on efficient Machine Learning techniques and is capable of approximating the final colour appearance based on arbitrary input parameters to each of the stages- The prediction phase can also be run backwards (meta-induction) to derive the best set of adjustments (set points) for achieving a desired output- Slight environmental changes can be incorporated into the predictions without the need for re-training- For adapting to significant environmental changes the system includes a novel batch- adaptivity strategy for re-training the internal models- All colour computations can - if needed - be based on a novel theoretical halftone model that was found to represent a good approximation of the Yule-Nielsen effect (i.e. the hue shift often occurring in intermediate printed halftones)- Finally, the framework contains diagnostic algorithms that can be used to optimise the sequence of ink applications and halftone patterns to achieve a desired tile appearance.